Image pickup device and still picture generating method

ABSTRACT

An image pickup device includes an optical system, an imaging element, an image processor, an input unit, and a controller. The optical system includes a focus lens. The imaging element generates an image signal from optical information that is input via the optical system. The image processor performs a predetermined process on the image signal generated by the imaging element, and then generates moving picture data including a plurality of frame images. The input unit receives input of a designated region on an image made by a user. The controller causes the image processor to generate the moving picture data while moving a focus position of the optical system, and then extracts a still picture that is in focus on the designated region from among the plurality of frame images included in the moving picture data.

BACKGROUND

1. Technical Field

The present disclosure relates to an image pickup device and a stillpicture generating method capable of recording an image in focus on animage region designated by a user.

2. Description of the Related Art

Digital cameras have functions including a focus bracketing function toperform continuous capturing while moving focal positions. This functionallows a user to select an image in a desired focus state aftercapturing images.

Unexamined Japanese Patent Publication No. 2004-135029 discloses adigital camera that has the focus bracketing function. This digitalcamera has a calculation section and a control section. The calculationsection calculates a focus evaluation value that indicates a focus stateof each of a plurality of images continuously captured by capturingusing the focus bracketing capturing function. The control sectionselects an image in a good focus state based on the focus evaluationvalue of each of the plurality of images calculated by the calculationsection, and then the control section controls an operation of arecording section to record image data indicating the selected image ona recording medium. This enables selection and recording of the image ina good focus state from the plurality of captured images.

SUMMARY

The present disclosure provides an image pickup device and a stillpicture generating method that allow the user to easily acquire a stillpicture in focus on a desired image region (subject).

The first aspect of the present disclosure provides an image pickupdevice. The image pickup device includes an optical system, an imagingelement, an image processor, an input unit, and a controller. Theoptical system includes a focus lens. The imaging element generates animage signal from optical information that is input via the opticalsystem. The image processor performs a predetermined processing on theimage signal generated by the imaging element to generate moving picturedata including a plurality of frame images. The input unit receivesinput of a designated region on the image made by a user. The controllercauses the image processor to generate the moving picture data whilemoving a focus position of the optical system, and then extracts a stillpicture that is in focus on the designated region from the plurality offrame images included in the moving picture data.

The second aspect of the present disclosure provides a still picturegenerating method in an image pickup device. The still picturegenerating method includes the steps of generating moving picture dataincluding a plurality of frame images while moving a focus position,receiving input of a designated region on an image made by a user, andextracting a still picture that is in focus on the designated regionfrom the plurality of frame images included in the moving picture data.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a configuration of a digital cameraaccording to the present disclosure.

FIG. 2 is a rear view of the digital camera.

FIG. 3A is a diagram illustrating movement of a focus lens in abracketing operation.

FIG. 3B is a diagram illustrating designation of a region to be in focusin an image made by a user.

FIG. 4 is a diagram illustrating cutting out of a still picture frommoving picture data.

FIG. 5 is a diagram illustrating a plurality of regions divided from animage.

FIG. 6A is a diagram illustrating a focus information table.

FIG. 6B is a diagram illustrating a header of the moving picture data.

FIG. 7 is a flowchart illustrating a focus bracketing operation.

FIG. 8 is a flowchart illustrating a moving picture recording operationin focus bracketing capturing.

FIG. 9 is a diagram illustrating a movement range of the focus lens inthe focus bracketing capturing.

FIG. 10 is a flowchart illustrating a still picture generating processfrom the moving picture data.

FIG. 11 is a diagram illustrating a screen to be displayed afterrecording of the moving picture data.

FIG. 12A is a diagram illustrating an operation of designating thedesired region to be in focus made by the user.

FIG. 12B is a diagram illustrating the operation of designating thedesired region to be in focus made by the user.

FIG. 13 is a diagram illustrating a display example of an image in focuson the region designated by the user.

FIG. 14 is a diagram illustrating a switching principle of images byforward frame-by-frame playback/backward frame-by-frame playback.

FIG. 15 is a flowchart illustrating a switching (frame-by-frameplayback) process of images by forward frame-by-frame playback/backwardframe-by-frame playback.

FIG. 16 is a flowchart illustrating a determination process of a framein focus for a divided region on which a frame in focus (position infocus) is not clear.

FIG. 17 is a diagram illustrating a determination method of the frame infocus for the divided region on which the frame in focus (position infocus) is not clear.

DETAILED DESCRIPTION

Exemplary embodiments will be described in detail below with referenceto the drawings as appropriate. However, a description more detailedthan necessary may be omitted. For example, a detailed description ofalready well-known matters and a repeated description regardingsubstantially identical components may be omitted. This is intended toavoid making the following description unnecessarily redundant and tomake it easier for a person skilled in the art to understand theexemplary embodiments. It is to be noted that the inventers provide theaccompanying drawings and the following description in order for aperson skilled in the art to fully understand the present disclosure,and do not intend to limit the subject described in the appended claims.

Exemplary embodiments of an image pickup device according to the presentdisclosure will be described below with reference to the drawings.

First Exemplary Embodiment 1. Configuration of Digital Camera

An example of an electric configuration of a digital camera according tothe first exemplary embodiment will be described with reference toFIG. 1. FIG. 1 is a block diagram illustrating the configuration ofdigital camera 100. Digital camera 100 is an image pickup device thatcaptures a subject image formed by optical system 110 including one ormore lenses with charge-coupled device (CCD) 140. Image data generatedwith CCD 140 undergoes various processes performed by image processor160 and is stored in memory card 200. The configuration of digitalcamera 100 will be described in detail below.

Optical system 110 includes a zoom lens and focus lens 111. Opticalsystem 110 can enlarge or reduce the subject image by moving the zoomlens along an optical axis. In addition, optical system 110 can adjustfocus of the subject image (focus state) by moving focus lens 111 alongthe optical axis. Lens driver 120 drives various lenses included inoptical system 110.

Lens driver 120 includes, for example, a zoom motor that drives the zoomlens and a focus motor that drives focus lens 111.

Diaphragm 300 adjusts a size of an aperture in response to user settingsor automatically to adjust an amount of light that passes through theaperture.

Shutter 130 is a section that blocks light that passes through shutter130 and reaches CCD 140. Shutter 130 constitutes an optical systemsection that controls optical information indicating the subject imagetogether with optical system 110 and diaphragm 300. Also, optical system110 and diaphragm 300 are accommodated in a lens body tube (notillustrated).

CCD 140 captures the subject image formed by optical system 110 and thengenerates image data. CCD 140 includes a color filter, a light-receivingelement, and an auto gain controller (AGC). The light-receiving elementconverts an optical signal concentrated by optical system 110 into anelectric signal to generate image information. The AGC amplifies theelectric signal that is output from the light-receiving element. CCD 140further includes a drive circuit for performing various operations suchas exposure, transfer, and electronic shutter. Details will be describedlater.

Analog-digital converter (A/D converter) (ADC) 150 converts the analogimage data generated by CCD 140 into digital image data.

In response to control performed by controller 180, image processor 160performs various processing on the digital image data that is generatedby CCD 140 and converted. Image processor 160 generates image data to bedisplayed on display monitor 220, and generates image data to be storedin memory card 200. For example, image processor 160 performs variousprocessing, such as gamma correction, white balance correction, and flawcorrection, on the image data generated by CCD 140. In addition, imageprocessor 160 compresses the image data generated by CCD 140 inaccordance with a compression format that complies with the 11.264standard, the Moving Picture Experts Group (MPEG) 2 standard, or thelike. Image processor 160 can be implemented by a digital signalprocessor (DSP), a microcomputer, and the like. In addition, based onthe image data generated by CCD 140, image processor 160 can generate,for example, image data of a moving picture with a number of pixels ofaround 4000×2000 (4K moving picture data). Image processor 160 canperform various processes to be described later on the generated 4Kmoving picture data.

Controller 180 is a control section that controls overall digital camera100. Image processor 160 and controller 180 can be implemented by asemiconductor device or the like. Controller 180 may be configured usingonly hardware and may be implemented by combining hardware and software.Image processor 160 and controller 180 can be implemented by amicrocomputer, a central processing unit (CPU), a microprocessor unit(MPU), a DSP, an application specific integrated circuit (ASIC), afield-programmable gate array (FPGA), and the like.

Buffer 170 functions as a work memory for image processor 160 andcontroller 180. Buffer 170 can be implemented, for example, by a dynamicrandom access memory (DRAM) and a ferroelectric memory.

Card slot 190 is a section for installing memory card 200 in digitalcamera 100. Card slot 190 allows connection between memory card 200 anddigital camera 100 mechanically and electrically.

Memory card 200 contains a flash memory, a ferroelectric memory, or thelike therein, and can store data such as image files generated by imageprocessor 160.

Built-in memory 240 includes a flash memory, a ferroelectric memory, orthe like. Built-in memory 240 stores a control program, data, and thelike for controlling overall digital camera 100.

Operating member 210 is a general term for a user interface thatreceives operations from a user. Operating member 210 includes a button,lever, dial, touch panel, switch, and the like that receive operationsfrom the user. In addition, operating member 210 includes a focus ringprovided in an outer circumference of the lens body tube. The focus ringis a member that receives a rotary operation made by the user for movingfocus lens 111.

Display monitor 220 can display an image (through image) indicated bythe image data generated by CCD 140 and an image indicated by image dataread from memory card 200. In addition, display monitor 220 can displayvarious menu screens for performing various settings of digital camera100 and the like. Display monitor 220 includes a liquid crystal displaydevice or an organic electroluminescence (EL) display device.

FIG. 2 is a diagram illustrating a rear of digital camera 100. FIG. 2illustrates release button 211, selection button 213, decision button214, and touch panel 222 as an example of operating member 210. Inresponse to the user operation, operating member 210 transmits variousinstruction signals to controller 180.

Input of a designated region on the image made by the user can bereceived using operating member 210 such as touch panel 222. It is to benoted that instead of using operating member 210, the input of adesignated region on the image made by the user may be received fromoutside of digital camera 100 by using a wireless communication functionof an unillustrated wireless communication unit such as Wi-Fi. In thiscase, a receiving unit of the wireless communication unit receives theinput of a designated region on the image. Operating member 210 such astouch panel 222 and the wireless communication unit such as Wi-Fi, whichreceive the input of a designated region on the image made by the user,are generically called an input unit.

Release button 211 is a two-step depression-type button. When releasebutton 211 is half-pressed by the user, controller 180 performsautomatic focus control (AF control), automatic exposure control (AEcontrol), and the like. Also, when release button 211 is fully pressedby the user, controller 180 records image data captured at timing ofdepression operation in memory card 200 or the like as a recorded image.Also, after release button 211 is half-pressed by the user, the user cancancel operations by not performing the full-press operation andcanceling the depression of release button 211.

Selection button 213 is a depression-type button provided in up anddown, left and right directions. By pressing selection button 213 of oneof the up and down, left and right directions, the user can move acursor or select various condition items displayed on display monitor220.

Decision button 214 is a depression-type button. When decision button214 is pressed down by the user while digital camera 100 is in acapturing mode or a playback mode, controller 180 displays a menu screenon display monitor 220. The menu screen is a screen for setting variousconditions for capturing/playback. When decision button 214 is presseddown while a setting item of the various conditions is selected,controller 180 decides the setting of the selected item.

Touch panel 222 is disposed such that it is superimposed on a displayscreen of display monitor 220 and detects a touch operation made by afinger of the user on the display screen. This allows the user toperform operations such as designation of a region on the imagedisplayed on display monitor 220.

1.1 Focus Bracketing Function

Digital camera 100 according to the present exemplary embodiment has afocus bracketing function to capture a moving picture while changing aposition in focus and to select and record one frame from a plurality offrame images that constitutes the captured moving picture. The focusbracketing function allows, for example, recording of the 4K movingpicture with the number of pixels of around 4000×2000. Thus, from themoving picture recorded in 4K, one frame image selected based on theuser designation is cut out to obtain a still picture.

Specifically, the focus bracketing function is to capture a movingpicture while moving focus lens 111 from a close end side toward aninfinite end side (or in a direction opposite thereto), that is, whilechanging the position in focus, as illustrated in FIG. 3A. Subsequently,as illustrated in FIG. 3B, user 50 designates subject 52 (that is,region) to be in focus in the captured image. As illustrated in FIG. 4,from among the plurality of frame images that constitutes the movingpicture, digital camera 100 selects one frame image based on thedesignation made by the user, and then cuts out and records the selectedframe image as a still picture. This allows acquisition of thehigh-quality still picture that is in focus on the subject (region)designated by the user.

For the purpose of the aforementioned focus bracketing, the presentexemplary embodiment divides image region 400 into a plurality ofregions as illustrated in FIG. 5. Then, for each of the divided regions,the frame in focus on the region (hereinafter referred to as “frame infocus”) is determined from among the plurality of frames thatconstitutes the moving picture, and then information regarding thedetermined frame in focus is recorded in a focus information table.Here, before recording (capturing) the moving picture in the focusbracketing operation, digital camera 100 performs a prescan operationand then detects the frame in focus on each divided region to generatethe focus information table.

FIG. 6A is a diagram illustrating data structure of the focusinformation table. Focus information table 60 stores a focus lensposition when focus is obtained on the closest end side (Pnear) in theprescan operation, a focus lens position when focus is obtained on themost infinite end side (Pfar), and frame numbers of the frames in focuson respective divided regions. Focus information table 60 is stored inheader 63 of moving picture data 65 obtained by capturing the movingpicture as illustrated in FIG. 6B.

2. Focus Bracketing Operation

The focus bracketing operation of digital camera 100 that has theaforementioned configuration will be described below.

With reference to a flowchart in FIG. 7, a moving picture recordingoperation in the focus bracketing operation of digital camera 100 willbe described. While the focus bracketing function is validly set inadvance to digital camera 100, full press of release button 211 by theuser will start the focus bracketing operation. The focus bracketingoperation includes a moving picture recording operation (S01) and astill picture generating operation (S02). In the moving picturerecording operation, digital camera 100 records (captures) a movingpicture while moving focus lens 111. In the still picture generatingoperation, digital camera 100 generates a still picture in focus on asubject (region) designated by the user from moving picture datarecorded in the moving picture recording operation. Each operation willbe described in detail below.

2.1 Moving Picture Recording Operation

FIG. 8 is a flowchart illustrating the moving picture recordingoperation (step S01). Controller 180 first performs the prescanoperation for detecting the position in focus on each divided region inthe image and creating the focus information table (S11).

In the prescan operation, controller 180 detects a contrast value ineach divided region of the image while moving focus lens 111 from theclose end to the infinite end (or in a direction opposite thereto)(refer to FIG. 5).

Then, controller 180 creates focus information table 60 based on aresult of the prescan. Specifically, when moving focus lens 111 from theclose end to the infinite end, controller 180 determines the frame withthe maximum contrast value for each region in the plurality of frameimages obtained as the frame in focus. Then, controller 180 records theframe number that indicates the frame in focus in focus informationtable 60. It is to be noted that when all the contrast values of theframes are lower than a predetermined threshold for one region, theframe in focus (that is, the position in focus) is not determined forthe region, and thus focus information table 60 records a predeterminedvalue indicating that the position in focus is unknown.

Controller 180 further determines the position in focus of focus lens111 on the closest end side (Pnear) and the position in focus of focuslens 111 on the most infinite end side (Pfar) when moving focus lens 111from the close end to the infinite end. Then, controller 180 recordsthese values in focus information table 60.

After the prescan operation is finished, controller 180 returns focuslens 111 to the close end side, and then records the moving picturewhile moving focus lens 111 within a predetermined range (S12). Here,the predetermined range is a range from the position in focus of focuslens 111 on the closest end side (Pnear) to the position in focus offocus lens 111 on the most infinite end side (Pfar), as illustrated inFIG. 9. By limiting a moving range of focus lens 111 to such a range,the moving picture is not recorded in the range in which focus is notobtained, reducing moving picture recording time. It is to be noted thatthe moving picture is recorded in accordance with a predetermined formatfor moving picture data. For example, the moving picture is recorded inaccordance with the MP4 standard (H. 264/MPEG-4 AVC standard).

After the moving picture recording is finished, controller 180 recordsin memory card 200 moving picture data 65 with focus information table60 recorded in header 63 (S13), and then controller 180 finishes themoving picture recording operation.

2.2 Still Picture Generation from Moving Picture Data

With reference to a flowchart in FIG. 10, the still picture generatingoperation (step S02) will be described. In the still picture generatingoperation, the still picture in focus on the subject (region) designatedby the user is generated from the moving picture captured in the movingpicture recording operation.

Controller 180 displays the moving picture that is recorded immediatelybefore on display monitor 220 (S21). For example, as illustrated in FIG.11, the moving picture that is recorded immediately before is displayedon display monitor 220. At this time, controller 180 may display one ofthe plurality of frame images (still picture) that constitutes therecorded moving picture.

The user operates touch panel 222 provided on the rear of the camera todesignate the subject (that is, region) the user wants to bring intofocus on the displayed image. For example, as illustrated in FIG. 12A,user 50 designates subject 52 as an object (region) to bring into focusby touching subject 52.

When the subject (that is, region) is designated by the user (YES inS22), controller 180 identifies the frame in focus on the regiondesignated by the user with reference to focus information table 60(S23). For example, as illustrated in FIG. 12A, when subject 52 isdesignated by the user, as illustrated in FIG. 12B, controller 180identifies region 42 corresponding to subject 52, and then acquires theframe number of the frame in focus on region 42 with reference to focusinformation table 60.

Then, controller 180 displays the frame image of the identified framenumber on display monitor 220 (S24). For example, when subject 52 isdesignated by user 50 in the image illustrated in (A) of FIG. 13, theimage that is in focus on designated subject 52 is displayed asillustrated in (B) of FIG. 13.

When the image displayed on display monitor 220 is the desired image,the user can decide the image as the still picture to be recorded bydepression of decision button 214. On the other hand, when the imagedisplayed on display monitor 220 is not the desired image, the user canswitch the image to be displayed on display monitor 220 by operations ofselection button 213 or the focus ring.

When the operation to switch the image is performed by the user (S27),in response to the operation, controller 180 switches the image to bedisplayed on display monitor 220 (S28). The user can cause displaymonitor 220 to display the desired image by performing the switchingoperation as appropriate. Details of this switching operation of thedisplay image will be described later.

When decision button 214 is pressed down by the user (S25), the image(frame image) that is being displayed is cut out as the still pictureand is recorded in memory card 200 (S26). For example, when decisionbutton 214 is pressed down, a confirmation message for the user may bedisplayed on display monitor 220. Then, when an instruction of the user(“YES”) is input for the confirmation message, controller 180 mayextract data of the frame image that is being displayed from the movingpicture data, and may record the data in memory card 200 as the stillpicture. It is to be noted that the still picture data may be recordedin built-in memory 240 or other recording medium instead of or inaddition to memory card 200. In addition, the still picture data may betransmitted outside of digital camera 100 by using the wirelesscommunication function of the unillustrated wireless communication unitsuch as Wi-Fi, instead of or in addition to being recorded in arecording medium such as memory card 200. In this case, the stillpicture data is transmitted outside of digital camera 100 from atransmitting unit of the wireless communication unit.

The moving picture data is recorded by a codec for moving pictures (suchas H.264 and H.265) and undergoes inter-frame compression. Accordingly,when cutting out the frame of the moving picture data as the stillpicture, controller 180 converts the frame image data into a format forstill pictures (for example, joint photographic experts group (JPEG)),and records the converted data.

As described above, the still picture data that is in focus on theregion designated by the user can be cut out from the moving picturedata. That is, the user can obtain the image that is in focus on thedesired subject.

2.2.1 Switching of Image (Frame-by-Frame Playback)

The switching operation of display images (frame-by-frame playback) ofsteps S27 to S28 in the flowchart in FIG. 10 will be described.

After the user designates the region to be in focus, when the imagedisplayed on display monitor 220 is not the image desired by the user,the user can switch the image to be displayed on display monitor 220 byoperating selection button 213 or the focus ring (S27 to S28). Forexample, by rotating the focus ring clockwise, the user can switch thedisplay image to the image frame before or after the current frame interms of time, that is, the user can perform frame-by-frame playback.

In particular, in the present exemplary embodiment, as illustrated inFIG. 14, when performing frame-by-frame playback in a forward direction(to a later direction in terms of time), the user performssingle-frame-by-single-frame playback. When performing frame-by-frameplayback in a reverse direction (to an earlier direction in terms oftime), the user returns to an I picture (Intra Picture) immediatelybefore. That is, when the frame-by-frame playback operation in theforward direction is performed, the frame image that is one frame afterthe currently displayed frame image is displayed on display monitor 220.On the other hand, when the frame-by-frame playback operation in thereverse direction is performed, among the I pictures which are beforethe currently displayed frame image in terms of time, the image of the Ipicture closest to the currently displayed frame image is displayed ondisplay monitor 220.

Such frame-by-frame playback control is performed because, when theimage to be displayed next is a P picture (Predictive Picture),processing time significantly differs between the frame-by-frameplayback in the forward direction and the frame-by-frame playback in thereverse direction. That is, in a case where the image to be displayednext is the P picture, when the frame-by-frame playback is performed inthe forward direction, the image to be displayed next can be generatedby adding the image information on the frame immediately after thecurrent frame to the image information of the current frame. However,when the frame-by-frame playback is performed in the reverse direction,the image to be displayed next needs to be generated by integration ofthe image information from the I picture before the current frame to theframe immediately before the current frame, requiring processing time.Therefore, when the frame-by-frame playback is performed in the reversedirection, the user returns to the I picture immediately before,reducing the processing time needed for display.

FIG. 15 is a flowchart illustrating the switching operation of displayimages (frame-by-frame playback). While the image that is in focus onthe region designated by the user is displayed on display monitor 220,when the user performs the frame-by-frame playback operation in theforward direction (YES in S51), controller 180 displays the frame imageone frame after the current frame (S52).

On the other hand, when the user performs the frame-by-frame playbackoperation in the reverse direction (YES in S53), controller 180 displaysthe image of the I picture closest to the current frame among the Ipictures which are before the current frame (S54). In this case, forexample, a display may be displayed on display monitor 220 for notifyingthe user that the display image has switched to the frame which is notthe frame immediately before.

Here, as an operating member for performing the frame-by-frame playback,a jog dial may be used other than the focus ring or the selectionbutton. In addition, a frame-by-frame playback button may be displayedon display monitor 220. By operating this frame-by-frame playbackbutton, the user can move the displayed image forward and backward interms of time.

Also, while the foregoing has described an example in which a group ofpicture (GOP) of the moving picture data includes only the I picture andthe P picture, the GOP of the moving picture data may further include abidirectionally predictive picture (B picture).

2.2.2 Processing when the Frame in Focus (Position in Focus) is Unknown

As described above, during creation of focus information table 60, whenall the contrast values of the frames are lower than the predeterminedthreshold for one region, the frame in focus (that is, the position infocus) is not determined for the region, and a predetermined valueindicating that the position in focus is unknown is recorded in focusinformation table 60.

In step S23 of the flowchart of FIG. 10, in the case of identifying theframe in focus on the region designated by the user with reference tofocus information table 60, when the position in focus on the region isunknown, controller 180 performs the following process to determine theframe in focus (that is, the position in focus).

FIG. 16 is a flowchart illustrating the process for determining theframe in focus on the region on which the position in focus is unknown.When the position in focus on the region of the subject designated bythe user is unknown (S71), controller 180 detects a region around theregion and on which the position in focus is unknown (S72). For example,as illustrated in FIG. 17, controller 180 detects another region group46 on which the position in focus is unknown around region 45 on whichthe position in focus is unknown.

Next, controller 180 detects region group 47 on which the position infocus (that is, the frame in focus) is clear around region groups 45,46; the positions in focus are unknown on region groups 45, 46 (S73).From the frames in focus on each of region group 47 on which thedetected position in focus (that is, the frame in focus) is clear,controller 180 determines the frame in focus with the largest number asthe frame in focus on region 45 on which the position in focus isunknown (S74).

As described above, the frame in focus can be determined on the regionon which the position in focus is unknown.

3. Advantageous Effects

Digital camera 100 according to the present exemplary embodimentincludes optical system 110, CCD 140 (one example of imaging element),image processor 160, operating member 210 (one example of input unit),and controller 180. Optical system 110 includes focus lens 111. CCD 140generates the image signal from optical information that is input viaoptical system 110. Image processor 160 performs a predeterminedprocessing on the image signal generated by CCD 140, and then generatesthe moving picture data including the plurality of frame images.Operating member 210 receives input of the designated region on theimage made by the user. Controller 180 causes image processor 160 togenerate the moving picture data while moving a focus position ofoptical system 110, and then extracts the still picture that is in focuson the designated region from among the plurality of frame imagesincluded in the moving picture data. Controller 180 may record theextracted still picture in memory card 200 (one example of thepredetermined recording medium).

As described above, digital camera 100 according to the presentexemplary embodiment extracts the still picture (frame image or frame infocus) that is in focus on the region designated by the user from themoving picture data captured while changing the focus position.Accordingly, the user can easily obtain the still picture that is infocus on the desired image region (subject) by designating the region ofthe image by touch. In addition, generating the still picture from themoving picture captured while continuously changing the focus positionallows the user to obtain the image that is in focus on any subjectincluded within an angle of view during capturing of the moving picture.

Also, digital camera 100 may store focus information table 60 (oneexample of the table) that manages each of the plurality of regionsobtained by dividing the image region of the image data and informationindicating the frame image that is in focus on each region inassociation with each other. Controller 180 can identify the frame imagethat is in focus on the region designated by the user with reference tofocus information table 60.

Also, before the moving picture recording operation, controller 180 mayperform the prescan operation to detect the focus state on each regionwhile moving the focus lens and to generate focus information table 60.

Also, controller 180 may record the moving picture while moving thefocus lens between the position in focus closest to the close end(Pnear) and the position in focus closest to the infinite end (Pfar)resulting from the prescan operation. This prevents recording of themoving picture in a range of the focus lens position that is not infocus, enabling efficient recording of the moving picture.

When the frame image that is in focus on one region is not obtained,controller 180 may determine the frame image that is in focus on the oneregion from the frame images for a region group around the one region,the region group including regions on each of which the frame image infocus is obtained. Accordingly, even when the region where focus is notobtained is selected, the image in focus on the region near the aboveregion is recorded as the still picture.

Digital camera 100 may further include display monitor 220 (one exampleof display) that displays the frame image for the user to designate theregion. The moving picture data includes the I pictures (one example ofa first image) generated without reference to information on other frameimages, and the P pictures (one example of a second image) generatedwith reference to the I pictures. When the user performs the imageswitching operation in the forward direction on the frame imagedisplayed on display monitor 220, controller 180 may display the frameimage one frame after the currently displayed frame image in terms oftime. Meanwhile, when the user performs the image switching operation inthe reverse direction on the frame image displayed on display monitor220, controller 180 may display the I picture closest to the currentlydisplayed frame image among the I pictures which are before thecurrently displayed frame image in terms of time. This enables quickimage display switching and allows user convenience to be secured.

Other Exemplary Embodiments

As described above, the first exemplary embodiment has been described asillustration of the technology to be disclosed in this application. Thetechnology in the present disclosure however is not limited to thisexemplary embodiment, and may be applied to exemplary embodiments towhich changes, replacements, additions, and omissions have been made asappropriate. It is also possible to make a new exemplary embodiment bycombining components described in the aforementioned first exemplaryembodiment and other elements. Therefore, other exemplary embodimentswill be illustrated below.

(1) In the above-described exemplary embodiment, in the focus bracketingoperation, the prescan operation is performed before recording of themoving picture, and focus information table 60 is created. Since theprescan operation allows recognition of the boundary position in focuswhere focus is obtained, an effective range to move the focus lensduring recording of the moving picture can be set, providing anadvantage that the moving picture can be recorded efficiently. However,the prescan operation is not essential, and focus information table 60may be simultaneously created during recording of the moving picture.This method provides an advantage that the angle of view does not changebetween a time of recording the moving picture and a time of generatingthe focus information.

(2) In the above-described exemplary embodiment, focus information table60 stores the position in focus on the closest end side (Pnear) and theposition in focus on the most infinite end side (Pfar). However, thesepositions in focus (Pnear, Pfar) do not necessarily need to be stored infocus information table 60, and may be held independently of focusinformation table 60.

(3) In the above-described exemplary embodiment, for each region of theimage, focus information table 60 stores information (frame number) thatindicates the frame in focus on the region (frame in focus). However,structure of focus information table 60 is not limited to this example.For each region of the image, the focus information table may store theposition of focus lens 111 when focus is obtained on each region. Inthis case, a second table may further be created indicating arelationship between the position of the focus lens and each frameduring recording of the moving picture. When the still picture is cutout, the frame image to be cut out from the moving picture can beidentified with reference to the focus information table and the secondtable.

(4) In the above-described exemplary embodiment, contrast AF is used asan automatic focus method; phase difference AF may also be used.

(5) The focus bracketing function disclosed in the above-describedexemplary embodiment is applicable to both types of digital cameras, aninterchangeable-lens camera and a lens integrated camera.

(6) In the above-described exemplary embodiment, description is madeusing a digital camera as one example of the image pickup device; theimage pickup device is not limited to this example. An idea of thepresent disclosure is applicable to various image pickup devices capableof capturing moving pictures, such as a digital camcorder, a smartphone,and a wearable camera.

(7) In the above-described exemplary embodiment, the imaging elementincludes a CCD; the imaging element is not limited to this example. Theimaging element may include an N-channel metal oxide semiconductor(NMOS) image sensor or a complementary metal oxide semiconductor (CMOS)image sensor.

As described above, the exemplary embodiment has been described asillustration of the technology in the present disclosure. For thispurpose, the accompanying drawings and detailed description have beenprovided. Accordingly, the components described in the accompanyingdrawings and detailed description may include not only componentsessential for solving problems but also components unessential forsolving problems, in order to illustrate the technology. Therefore, itshould not be acknowledged immediately that those unessential componentsbe essential because those unessential components are described in theaccompanying drawings and detailed description. Also, since theaforementioned exemplary embodiment is intended to illustrate thetechnology in the present disclosure, various changes, replacements,additions, omissions, and the like may be made within the scope of theappended claims or equivalents thereof.

The present disclosure is applicable to the image pickup device andstill picture generating method capable of capturing moving pictures.Specifically, the present disclosure is applicable to various imagepickup devices and still picture generating methods capable of capturingmoving pictures, such as a digital camcorder, a smartphone, and awearable camera.

What is claimed is:
 1. An image pickup device comprising: an opticalsystem comprising a focus lens; an imaging element that generates animage signal from optical information that is input via the opticalsystem; an image processor that performs a predetermined processing onthe image signal generated by the imaging element to generate movingpicture data that includes a plurality of frame images; an input unitthat receives input of a designated region on an image made by a user;and a controller that causes the image processor to generate the movingpicture data while moving a focus position of the optical system, andextracts a still picture that is in focus on the designated region fromamong the plurality of frame images included in the moving picture data,wherein: the controller generates a table for associating (i) the focusposition of the optical system when each of frame images is generatedand (ii) a focused region of each of the frame images, the focusedregion being one of regions divided from an image region of each of theframe images, and with reference to the table, the controller identifiesa frame image that is in focus on the designated region as the stillpicture, and before causing the image processor to generate the movingpicture data, the controller performs a prescan operation, in which apre-moving picture is captured, while moving the focus position of theoptical system, the controller determines a position of the opticalsystem in focus closest to a close end and a position of the opticalsystem in focus closest to an infinite end, resulting from the prescanoperation.
 2. The image pickup device according to claim 1, wherein thecontroller uses a result of the scan operation for generation of thetable.
 3. The image pickup device according to claim 1, wherein thecontroller generates the moving picture data while moving the focusposition of the optical system between a position in focus closest to aclose end and a position in focus closest to an infinite end, resultingfrom the scan operation.
 4. The image pickup device according to claim1, wherein when a frame image that is in focus on one region of theplurality of regions is not obtained, the controller determines theframe image that is in focus on the one region from the frame images fora region group around the one region, the region group including regionson each of which the frame image in focus is obtained.
 5. The imagepickup device according to claim 1, further comprising a display thatdisplays each of the frame images for inputting the designated region,wherein the moving picture data includes first frame images generatedwithout reference to information on other frame images and second frameimages generated with reference to the first frame images, when the userperforms an image switching operation in a forward direction on a frameimage currently displayed on the display, the controller displays one ofthe frame images that is one frame after the currently displayed frameimage in terms of time, and when the user performs an image switchingoperation in a reverse direction, the controller displays one of thefirst frames that is image closest to the currently displayed frameimage out of the first frame images that are before the currentlydisplayed frame image in terms of time.
 6. The image pickup deviceaccording to claim 1, wherein the controller records the extracted stillpicture in a recording medium.
 7. The image pickup device according toclaim 1, wherein the controller records the extracted still picture thatis in focus on the designated region in a recording medium.
 8. The imagepickup device according to claim 1, wherein when there is a frame infocus on each of the divided regions, the table stores a frame number ofthe frame in focus on each of the divided regions.
 9. A still picturegenerating method in an image pickup device, the still picturegenerating method comprising the steps of: generating moving picturedata including a plurality of frame images while moving a focusposition; generating a table for associating (i) the focus position wheneach of frame images is generated and (ii) a focused region of each ofthe frame images, the focused region being one of regions divided froman image region of each of the frame images; receiving input of adesignated region on an image made by a user; and extracting a stillpicture that is in focus on the designated region from the plurality offrame images included in the moving picture data, wherein: withreference to the table, identifying a frame image that is in focus onthe designated region as the still picture, and before generating themoving picture data, performing a prescan operation, in which apre-moving picture is captured, while moving the focus position,determining a position in focus closest to a close end and a positionclosest to an infinite end, resulting from the prescan operation.